The present disclosure relates to techniques for calculating the tension of a belt and for calculating the natural frequency of the belt for tensioning the belt.
To prevent wear in a belt looped over pulleys and other components and a reduction in transmission efficiency of the belt, the belt needs to keep having an appropriate tension. Thus, the tension of the belt needs to be measured. In a known technique, the tension of a belt is measured based on the natural frequency (the frequency of natural vibration) of the belt to enable simple measurement of the tension. For example, Japanese Unexamined Patent Publication No. 2005-257350 describes a device that includes a microphone used to detect vibrations of a belt through sound waves and calculates the tension in accordance with a predetermined expression.